Adie's pupil is characterised by pupil dilatation, segmental iris palsy, light-near dissociation, and slow re-dilatation. Most commonly, tonic pupils are unilateral and idiopathic, but can be caused by orbital disorders and autonomic neuropathies. There are only a few case reports of tonic pupils in patients with Sjö gren's syndrome, caused by an autoimmune ciliary ganglionitis. The authors report on two cases with bilateral tonic pupils as the initial manifestation of primary Sjö gren's syndrome. Both patients presented with blurred vision, bilateral tonic pupils, and sicca symptoms. The findings suggest that Sjö gren's syndrome should be considered in patients presenting with bilateral Adie's tonic pupils.